Thermal Burst Synthesis of High-Performance Si Nanotube Sheets for Lithium-Ion Batteries

One of the drawbacks of Si-based battery anodes is poor cycle stability due to volume expansion of the anode material. To overcome this limitation, we propose a novel strategy of Si nanotube sheet synthesis using the thermal burst method. Herein, SiO2 nanotubes are prepared using the hard template method; subsequently, Si nanotube sheets are produced during the thermal burst caused by magnesiothermic reduction, which occurs because nanotubes are broken by ZnO with a larger thermal expansion coefficient. The electrochemical test results indicate that the Si nanotube sheets possess excellent electrochemical properties. The discharge specific capacity can reach 712.7 mAh g–1 even at the current density of 5 A g–1. Moreover, after carbon coating, a discharge capacity of 695.9 mAh g–1 is retained after 400 cycles at 1 A g–1 and the capacity retention of full batteries can reach 81.78% after 50 cycles at a rate of 0.5 C. Thus, the Si-based anode electrode with excellent electrochemical performance can be prepared by the thermal burst process, and this strategy can be applied to the preparation of other anode materials.